Sorry for your loss. Bring them, it will be fine. An Irish funeral is a beautiful, actually life affirming occasion that is very different from what you will be used to in the UK. They are family occasions with lots of children around. For the Irish, death is just a part of life, and even a funeral after a tragic death is still a beautiful, loving occassion.
Depending on whether its a country or town wedding, there will be a wake the night before with the (possibly) open coffin either at the funeral home or the house. I promise you, this is not a scary thing, and you wont be under any pressure to go near the coffin if you dont want to. Neighbours will come from miles around to greet you and pay their respects. If the funeral is on a weekday, this is the way people can pay their respects without having time off work for the actual service the next day.
If the wake is in the country and takes place in the home, there will be Irish mammies that seem to appear from nowhere with trays of sandwiches and cups of tea for anyone who comes by.
Either way, there will be decades of the rosaries said at frequent intervals.
The day of the funeral, more people will arrive to the church, where there will be a full funeral mass before the walk to the cemetary. Then there will be a reception afterwards, which I've noticed in recent years, are for invited family and may be a sit down hot meal in a local hotel.
Honestly, please go and take the kids. It will not be stressful and your husband will need your support. If he comes from a big family, I'd bet there will be lots of teenage cousins only too happy to mind the babies for an hour for a few euro! In the UK, people are a bit weird and stressy about death and funerals, but in Ireland, they are generally a pretty relaxed event. Irish people also dont get all worked up about wearing black and all that either, just dress smartly.
It will undoubtably be sad, but I promise you, it wont be difficult.